Hypodermic syringe



July 1, 1958 M. J. COHEN ET AL 2,841,144

HYPODERMIC SYRINGE Filed Feb. 12. 1954 a'y. l.

INVENTORS #71770 L7. Coben BY W M ATTORNEY United States -Patentl l' 2,841,144 HYPoDERMIC SYRINGE Milton J. Cohen, Washington, D. C., and Robert McConnaughey, Chevy Chase, Md.

Application February 12, 1954, serial No. 409,829 7 claims. (ci. 12s-21s) The object of this invention is to provide `a cheap, disposable hypodermic syringe, self-contained in a rigid tubular. cartridge of glass or other suitable material, wherein the needle, attached to a movable piston covered by a protective cap and with the lumen occluded, is carried inside the tubular cartridge, as shown in Figure 1, for protection and compactness during shipment, storage and handling. When the syringe is to be used, the needle, carried by the forward piston, can be moved forward by pressure of the column of liquid medicament, actuated by a plunger, until the needle projects out of the forward end of the cartridge to the required length and is there held rmly in position for use. In that position, upon removal of the protective cap, the needle may be ini serted into the patient and the injection made.

The objects and advantages of this invention are:

(1) Complete protection of the needle against physical damage and contamination before use.

(2) Ultimate compactness of the syringe unit vprior to use.

(3) A simple means whereby the syringe may be easily prepared for use.

(4) Cheapness of manufacture.

(5) A cheap and simple means whereby the plunger shaft may be easily attached to or detached from the plunger.

Referring now to the annexed drawings, which are made a part of this application and in which similar parts are indicated by similar reference characters:

Fig. 1 is a longitudinal section of the syringe of our invention, l

Fig. 2, a detail of the needle and its supporting means,

Fig. 3, a similar view of a modified form of this part of the invention,

Fig. 4, a section of a modified form of the needle end of the syringe,

Fig. 5, a section of the syringe showing the preferred form of plunger,

Figs. 6, 7 and 8, modifications of the plunger, and,

Figs. 9 and 10, sections of still further modications of the needle support.

The operative parts of the device are shown as being contained in a tubular Acartridge 1S of glass or other rigid material, having an internal neck or constriction 16 at its forward end. Prior to use, 'the needle 18 is entirely contained within the tube 15 and is attached to a metal connector disk or cup 19 by swaging or by a hollow rivet 20 and to a floating piston 17, slidable in the cartridge tube, by inserting the portion of the needle that projects rearward from the connector 19 through the piston 17, the connector 19 being held'rmly against the forward face of the piston 17 Means are provided for occulding the lumen of the needle by a puncturable plug of soft rubber or other suitable material 14. This occluding means islheld rmlyvin position over the point of the needle by a rigid cylindrical sleeve 28 of metal or other suitable material which surrounds the portion of the needle projecting forward from -the connector 19. The protectiveV sleeve 28 is removably attached to connector 19 as by a jam taper t, or otherquickly detachable means. An annular depression at 28"limits rearward movement of plug 14. Thus assembled', the pistion 17, the' con- 2,841,14 Patented July l, 1958 nector 19:, the needle 18 attached, the occluding."

sometimes called the needle assembly. The occluding of plug 14. Thus assembled, the piston 17, the connector 19`Lse'al off thechannel of the needle against expulsion of the liquid medicament until the cap has been removed by the user, thereby permitting the entire needle assembly to be pushed forward by pressure on the plunger shaft 23, transmitted to the piston 17 through the column of liquid medicament 21 which is carried in the tube 15 immediately behind the piston 17. Behind the medicament 21 is a plunger 22 which serves as the rear closure of the cartridge 15.

In the form of the invention illustrated in Fig. 1, the rearward plunger 22 is actuated by a hollow tubular plunger shaft 23 having an internal ange 35 to engage in an external annular groove 36 in the mushroom-shaped nib 27 of the rearward plunger 22. When so assembled, the shaft 23 and the rearward plunger 22 operate as a plunger to force the medicament through the cartridge, pushing the needle assembly ahead of it through the cartridge, until the shoulder of the connector 19 abuts the internal constriction 16 at the forward end of the cartridge, and the needle 18 with its protective sheath 28 andv occluding plug 14 in place, projects outside the cartridge.

Prior to actuation of the plunger to drive the needle forward out of the cartridge in the manner described, the opening in the forward end of the cartridge tube would be closed by a frictionally held cap 24, as shown in Fig. l. In either case the occluding means could be pushed from the device by the forward movement of the sheath 28 surrounding the needle when the plunger is actuated, or it could be removed by hand immediately before actuation of the plunger to move the needle forward. The purpose of the cap or plug closing the forward opening of the cartridge tube is to seal the forward portion of the cartridge, prior to use, against the entrance of any contaminating substance, and any suitable means of occluding the forward aperture of the cartridge in such manner as to exclude the entrance of contaminants and at the same time permit easy removal of the occluding cap or plug will serve the purpose of the invention.

In the form illustrated in Fig. l, the needle attachment cup 19 is placed over and around the cylindrical or conical forward portion yof the piston 17 and is rolled or crimped into a groove 23 1in the piston.

In the Aform illustrated 1in Fig. 2, the 4cup `to which the needle is attached is held to the pist-on, before operation of the syringe, by friction of the cup 1'9" and the shaft of the needle 18 in firm contact lwith the piston 17 'In the 'form illustrated -in Fig. 3, the needle fis riveted or swaged to a cup 19 which rests against the forward end of t-he piston i17" and ywhile at rest, before operation `of the syringe, is held in position solely by friction of "the needle 18 which is gripped by the rubber of the piston 17". v

IIn the case yof all of the forms illustrated in Figs. 1, 2 and 3, when the needle has been pressed to the forward position ready for use as shown 4in Fig. 4, it is held firmly in that position 'between the neck constriction and the ."be of any `form or material suitable for pushing the plunger 22 forward, is applied to the rear end of the plunger 22 and pushed forward into the cartridge 15. The pressure thus/applied by the plunger shaft is trans- `mitted iby the plunger 22 and the column of liquid medicement -21 to the forward piston *17, 17 or 17 holding the cartridge until the shoulder ofthe needle` attachment disk or cup 19, 19 or 19" rests against the neck or constriction 16 at the forwardend of `the cartridgeI 15,

During this operation the lumen 26 of the needle 18 remains occluded `by theV plug 14 ofvrubber or other material having ygenerally similar characteristics. TheV plug 14 is held firmly in position over the point of the needle by the sleeve 28. The sleeve 28 is rmly `but removably attached by `a jam taper fit or `by threads or lugs or other suitable means to the projecting forward portion of' t-he needle connector cap ordisk 19. As a consequence of this attachment of the sleeve to `the connector cap ordisk 19 at one end and to the needle occluding plug 14` at the other, when Ipressure is applied to the rear face of `the piston 17 by the column of medicament 21 actuated `by the plunger 22, the w-hole needle assembly will move forward until the shoulder of the needle connector cap or disk is forced against the internal shoulder formed 'by the neck or constriction at the forward endfofV the cartridge. When the needle has reached this position the sleeve 28 and the plug 14 may be removed either together, the needle inserted into the patient and the injection made in the usual fashion. y I

In cases where it is desired to aspirate the syringe to determine Whether a vein has been pierced, therear plunger 22 would be so formed (by having a projecting mushroom-shaped grooved nih `27, Fig. 5, a mushroomshaped cavity 37, Fig. 6, a projecting threaded portion 29j, Fig. 7,l a recessed threaded cavity 30, Fig. 8), or such` other suitable means of attachment as to permit a Efirm but easy attachment of the plunger shaft 23 or of its modied forms 23a, 23h, 23C, to the plunger 22 or its modified 'forms 22a, 22h, 22C shown in Figs. 6, 7 and 8 respectively, thereby permitting the various pistons to ybe moved either forward or 'backward within the barrel of th-e syring at the 'will of the user.

A further variation of the invention illustrated in Figs. 9 and 10 has the forward piston formed as a hollow cylinder 31 with an integral membrane across its central passage, either at its forward end at 31' as illustrated in Fig. 9 or across its rear end at 34 as illustrated inl Fig.l 10. This membrane serves as an 4internal seal separating the medicament contained in t-he cartridge from contact "with the metal of the needle connector cap or disk 19, and the lumen of the needle 18. Pressure of the column of medicament 21 actuated by the rear plunger 22 will balloon the membrane either -into the central cavity of the piston 3'1, Fig. 10, or into thegcavity of ythe needle connector 19, Fig. 9, where it will be ruptured vby contact with the rearward point of the needle 18 projecting into the cavity, thereby opening a channel through which the liquid medicament can flow into the lumen of the needle and, -upon removal of the sleeve 28 and plug 14 and application of further pressure of the plunger 22, through the channel of the needle into the patient. lIn these `latter yforms the -forward piston is an adaptation of the membrane piston seal covered by our patent application No. 374,012, filed August 13, 1953, and is regarded as an extension and an improvement of the invention 'described in that application'in that the membrane piston as described in this application provides a means of holding the needle in the syringe in addition to its performance of its other function-s described in the prior application.

The net overall resul-t is a self-contained syringe cartridge with a sterile needle ready for use and fully protected within the cartridge, the entire apparatus, exclusive of the plunger, when made in a size suitable Vfor a 1 cc. dose of medicament and with a needle designedfor 3% inch projection, being approximately the same size as a Isingle king-size cigaret and, in general, similarly shaped, The essential features of this invention are: (a) the idea of attaching the needle directly to a slidable piston so that the needle may be contained within `them-barrel of the syringe until it is. ready to used,

y4` thus achieving both maximum protection of the needle against damageand contamination andthe utmost feasible compactness of the package.

(b) the idea of moving 'the needle forward by hydraulic pressure of the column ofy liquid medicament to a point where it is rmly held in position projecting from the cartridge ready for use, thus affordingthe advantages of simplicity of design, cheapness of construction, ease of operation, and elimination of mechanical means of action to move the needle into a usable position, other thanthe column of liquid medicament actuated by the ordinary motion of pushing the plunger forward.

(c) the idea ofV a one-piece molded plunger of natural or synthetic rubberv or other substance having generally similar qualities so designed, with a projecting mushroom-shaped nib of the same material, as to permit ready attachment of the plunger or detachment from the plunger of a simple tubular plunger shaft having an internal' flange at its forward Aend corresponding to the external annular groove of the mushroom-shaped nib of the plunger, the manufacture of such a one-piece molded piston being substantially cheaper and simpler than the manufacture of detachable plungers having the connecting means'of different materials molded into or otherwiseattached to the plunger.

It will be obvious to those skilled in the art that many changes may be made in the devices disclosed herein, all without departingfrom the spirit of the invention; and therefore we do not limit ourselves toy what is shown in the drawings and described in the specification, but only as indicated by the appended claims.

Having thus fully described our invention, what we claim is:

1. A hypodermic syringe having a tubular open-ended outer cartridge, a plunger mounted for reciprocation in one end of said cartridge, a floating pistonl adjacent the other end of the cartridge providing with the plunger a compartment for liquid, a hypodermic needle extending through the piston into communication with said compartment, a cup removably attached to said piston and supporting said needle, a sleeve surrounding said needle and a plug carried by said sleeve in position to close the orifice Vinthe needle.

2. A device as in claim 1, including a cap closing the second-named end of the outer casing.

l5'. A device asy in claiml, said plug consisting of. soft rubber.

4. A device as in claim 1, wherein said cup hasA an inclined surface at the end remote from said compartment for concentric engagement by said sleeve.

5. A device as in claim 4, wherein the sleeve is frictionally connected to said cup.

6. A device as in claimll including a hollow rivet mounted in said cup, said needle passing through said rivet vand being attached thereto.

7. A device as in claim 1 wherein said plunger has a exible head and plunger shaft for said head is releasably attached to said plunger.

References Cited in the le of this patent UNITED' STATES PATENTS 1,288,174 Pittenger Dec, 17, 1918 1,455,047 Go'old May 15, 1923 1,738,146 Kulk D120-l 3, 1929 1,961,490 Hein June 5, 1934 2,408,323 Lockhart Sept. 24, 1946 2,460,039 Scherer et al. J an. 25, 1949 2,473,734 S1:r1ith, Y June 21, 1949y 2,671,449 Dann Mar. 9, 1954 2,671,450 Dann Mar. 9, 1954v 2,707,466 Hoskins et al May'3, 1955 FOREIGN PATENTS 316,516 Great Britain -f-f-,e-.f June 5,. 1.930 

